Spark plug



June 23, 1925.

, J. C. NEWTON SPARK PLUG Filed July 21. 1922 a a/Vwzw,

- Piuma .im 23,1925

4UNITEDv STATES.

Joan' c. lawson, or immens, mason.

arm une.

' Appusan ma .my ai, ma semi l. wam. l

Toallwhomtmay concern.'

Be it known that I JOHN C. Nnw'mN, a citizen f the Uni Minneapolis, in the county of Hennepin and State of Minnesota, have invented new andv so that a plug structure is provided in which electrodes and insulators may be removed or interchanged and cleaned without removing the shell 'of the spark plug from the engine block.

i Another object of the invention is to provide a spark plug of this character, wherein the ing thereof, in order to change the relation of the sparkin points of the electrodes, and a device whic may be manufactured at a relatively small cost.

To the attainment of the foregoing, the invention. consists in the improvement as hereinafter described and definitely claimed.

In the accompanying drawings, forming part of this specification Figure l-is a side elevation of a plug constructed in accordance with my invention; y

Figure 2 is a diametrical section of the same. c

Figure 3 is a detail elevation showing one dielectric member of the plug and its ap,

purtenances.

Fi ure 4 is a transverse section taken in the p ane indicated by the line 4-4of Figure 2. l

, Similar numerals of reference designate corresponding parts in Figures l to 4 to which reference will first be made.

Among other elements my novel plugcomprises a metallic bushing 1, exterior y and interiorly threaded at 2 and 2, res ectively, and interiorly and exteriorly shou dered at 3.and 4, res ectively. The plug also comprises a loc ing nut 5 made in two semi-` circular sections, Figure 1, and two dielectric members 6 of semi-circular cross-section and made b preference of mica for the sake of durabilit At intermediate points in their length -e dielectric members 6 are provided with exterior lateral projections 7, and

States, residing atv and outer ends o arts are removable to permit easyy cleaning of the parts as well as interchang-k vposite pole of the sourcev of aboveand below said projections are arranged washers 8 of copperorother appropriate metal or alloy or other material, each.`

of the said washers 8 being in two semicircular sections.v Secured in fixed mannerin and extendin longitudinally throu h the dielectric mem rs 6 are electr I es 9. These electrodes iprotrude beyond thenner the members 6;'-the inner end portions of the electrodes being directed laterally inward and spaced vapart `to aord a spark gap, `and the. outer end portions of .PATENT ori-fics! the electro s being div'eged as indicated byY 10 and extended outwar dg through the oppositely beveled outer ren 11 ofthe members 6 whereby short-circuitng between the outer end ortions of the electrodes is pre` eluded. T e said electrode portions 10 are threaded as .shown to receive vnuts v12 lfor clampin wires against washers.13m`ounted on the e ectrodes and yopposed to the beveled ends of the dielectric members 6. e,

In virtue of the peculiar plu construction set forth it will be observed it at when the locking nut 5 is turned out of thev bushing `1, and the dielectric members 6 are withdrawn from the bushin the said members 6 may be separated and i either member 6 or its electrode 9 is impaired, a new member 6 ca ing an electrode 9 may be substituted for t e impaired member. Again when the members 6 are' removed from the bushing 1 and separated'as stated, the said members 6 and their electrodes ma be thoroughly cleaned with ease and ex ition.

In the practical use of the plug described one of the electrodes 9 is .electrically connected with one of the poles of a source of electric ener and the other electrode is either electrlcally connected with the openergy or `is appropriately grounded.

I have entered into'a detailed description of the construction and relative arrangement of the parts embraced in the lpresent and preferred embodiments of my invention in order to impart a full, clear and exact understanding of the said embodiments. I do not desire, however, to be understood as confining myself to the specific construction and relative arrangement of arts inasmuch as in the future practice o the invention various changes and modifications may be made such as fall within the sco of my invention as defined in my appen ed claim.

Havino' described my invention, vwhat I claim and desire to secure by Letters-Patent,

A spark plug structure comprising a bushing having an interiorly located annular shoulder disposed at an acute angle to the axis of the bushing, a pair of dielectric members mounted in the lbushing and provided at their sides with projections having bevelled edges, each of said members being provided with a sparking electrode, sai members having flat faces adapted to beur against each other and being located at the sides of the member opposite those sides at which the pro'ectons are rovided, and a sectional glan mit screwe into the bushing and having a bevelled surface disposed opposite the rojection, the parts being so assembled an arranved that when the nut is tightened in the busng', the shoulder and the bevelled surface of the nut cooperate with the bevelled surfaces of the pro`ections whereby the flat faces of the dielectric members are forced in close contact with each other. v

In testimony whereof, I aflix my signature.

JoHN o. NEWTON. 

